BENDIX TCH-003-039 User Manual

Technical Bulletin

Bulletin No: TCH-003-039-A Effective Date: 11/5/96 Cancels: NA Page: 1 of 1

Subject:

R-12/R-14 RELAY VALVE - 10 PSI DIFFERENTIAL

OBSOLESENCE

All R-12 and R-14 relay valves which incorporate a 10 psi differential (crack pressure) were obsoleted in 1995.
The R-12 and R-14 part numbers that were affected by the obsolescence are;

102849 R-12
103137 R-14
103139 R-14
103195 R-12
103229 R-12
108490 R-12

When it is necessary to replace these valves and the 10 psi crack pressure must be maintained, it is suggested that
R-6 relay valve, part number 280243, be considered. This R-6 relay valve incorporates a 10 psi crack pressure
but does not have the anti-compound (quick exhaust) feature that is part of the R-14 relay valve.

Important: When replacing an R-12 or R-14 that is connected to four service chambers (i.e. tandem axles), it
will be necessary to use two R-6 relays (one for each axle of the tandem). This is necessary to maintain the
vehicle manufacturer’s brake application and release timing.

For additional information on the R-6, R-12 and R-14 refer to catalog pages 03-B-3, 03-B-4C to 03-B-4F
respectively.